A multiple input multiple output (MIMO) architecture of a system can be employed to improve the throughput of broadband wireless networks. In conventional cellular networks, frequency reuse among nearby cells can result in inter-cell interference (ICI) and degrade the performance. To overcome these problems, base station (BS) cooperation can be employed. For exemple, assuming perfect backhaul connection, a network of multiple cells can be viewed as a virtual MIMO system, and the mobile devices/users in the multiple cells can be jointly served by multiple BSs.
In a resource unit, the cooperating BSs in one cluster can jointly select a set of active mobile devices/users. Precoding can be applied for the selected mobile devices/users. The precoding can be applied such that the signal intended for each of the selected mobile devices/users is received with lower interference than the interference for the signals for which precoded is not applied. The precoding can be linear precoding, such as for MU-MIMO based on block diagonalization (BD), in which the signal for each user is projected onto the nullspace of the augmented channel matrix of other mobile devices/users. Precoding can be performed for clustered MIMO networks with inter-cluster coordination. Additionally, greedy user selection algorithms can be employed for single-cell multi-user MIMO (MU-MIMO) networks based on BD precoding. However, the above described precoding techniques assume perfect channel state information at the transmitter (CSIT). To achieve, or at least approximate, CSIT, feedback from the mobile devices/users is employed. Unfortunately, the overhead introduced by CSIT feedback limits the performance of MIMO systems. For multi-cell networks with large number of mobile devices/users, further feedback reduction is desired. Other problems with the state of the art and corresponding benefits of some of the various non-limiting embodiments may become further apparent upon review of the following detailed description.